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The aim of this paper is to establish a fabrication process for non-volatile memory (NVM) transistors using ZnO nanoparticles, polymethylsilsesquioxane (PMSSQ) and soluble pentacene. ZnO nanoparticles mixed into the PMSSQ solution are used to create a nanocomposite layer for charge trapping in the NVM. It has been demonstrated that the nanocomposite layer in a metal–insulator–semiconductor structure can cause a hysteresis of ~ 6 V in a capacitance–voltage (C–V) plot, indicating a significant charge trapping capability. A threshold voltage shift of ~ 2.3 V between a programmed and erased NVM transistor and a carrier mobility of ~ 0.002 cm2/V-s are achieved. At present the fabricated NVMs have a limited life cycle of 4 program/erase cycles.

This paper discusses the application of a DC sputtered ZnO thin film as a dielectric in an optically transparent non-volatile memory. The main motivation for using ZnO as a dielectric is due to its optical transparency and mechanical flexibility. We have established the relationship between the electrical resistivity ( ρ ) and the activation energy ( E a ) of the electron transport in the conduction band of the ZnO film. The ρ of 2 × 10 4 –5 × 10 7 Ω-cm corresponds to E a of 0.36–0.76 eV, respectively. The k -value and optical band-gap for films sputtered with Ar:O 2 ratio of 4:1 are 53 ± 3.6 and 3.23 eV, respectively. In this paper, the basic charge storage element for a non-volatile memory is a triple layer dielectric structure in which a 50 nm thick ZnO film is sandwiched between two layers of methyl silsesquioxane sol–gel dielectric of varying thickness. A pronounced clockwise capacitance–voltage ( C–V ) hysteresis was observed with a memory window of 6 V. The integration with a solution-processable pentacene, 13,6-N-Sulfinylacetamodipentacene resulted in an optically transparent organic field effect transistor non-volatile memory (OFET-NVM). We have demonstrated that this OFET-NVM can be electrically programmed and erased at low voltage (± 10 V) with a threshold voltage shift of 4.0 V.

This paper demonstrates the novel application of d.c. sputtered zinc oxide (ZnO) as a charge trapping dielectric material for the application of an organic thin film transistor (OTFT) based non-volatile memory (NVM). The motivation of using ZnO as a dielectric is due to its chemical stability and optical transparency, enabling future development of transparent electronic devices. Unbalanced magnetron d.c. sputtering with Ar:O"2 ratio of 80:20 was used to obtained a ZnO dielectric of 50nm thick. The ZnO has an optical band gap of 3.23eV, resistivity and k-value of 5x10^7@W-cm and 50, respectively. The ZnO sandwiched between two layers of low-k methyl-silsesquioxane (MSQ) sol-gel dielectric creates a triple layer dielectric structure for charge storage. A solution-processable pentacene, 13,6-N-Sulfinylacetamodipentacene, was used as an active layer of an OTFT-NVM. It has been successfully demonstrated that this OTFT-NVM can be electrically programmed and erased at a low voltage.

Polyaniline (PANI) nanotubes configured as a field effect transistor (FET) exhibits a p–n junction diode behavior. The forward-bias current can be modulated by a gate voltage; turning on at negative gate voltage and turning off at positive gate voltage. An energy band diagram model has been proposed to explain the rectifying effect of the PANI nanotubes FET (PNT-FET). All the four different forward bias conduction mechanisms of a typical p–n junction diode can be identified for this PNT-FET using a semi-log graph to confirm this resemblance.